In the restaurant, tableware rental, and food catering industries large numbers of dishes must be racked, washed and stacked. The sheer volume of such activity demands that dish racks be designed for ease and speed of loading and unloading. At the same time, they must be constructed so that likelihood of breakage is minimized during loading, unloading and transport. Where the racks are incorporated into or used in dishwashers, they must also be designed so that water sprays effectively clean the dishes and provide good drainage.
An early dish rack specifically designed for use in a dishwasher is shown in U.S. Pat. No. 1,595,421. The dish rack here has a frame that supports a set of mutually spaced, parallel rods between which dishes are placed uprightly. Handles are provided for use in placing the rack, loaded with dishes, into and out of a dish washing machine. This type of rack, specifically designed for use in dishwashers, has several deficiencies. Probably foremost amongst these is its inability to hold different size dishes in a secure manner. The support rods are simply placed apart a distance sufficient to accommodate a selected maximum sized dish in order that it may be used to hold that size dish and smaller dishes. This results in good support for the larger size dishes but only loose support for the smaller dishes. It also sacrifices economy of space for the smaller dishes.
Another dish rack design is shown in U.S. Pat. No. 3,303,934 which is permanently mounted in a dishwasher. It has several sawtooth shaped support rods, selected grouping of which are used to support different sized dishes. Depending on their size, dishes are supported on as few as two or as many as six rods. This design scheme is to provide a sufficiently large number of supports so that several combinations are available to hold dishes of various sizes in a reasonably secure and separated manner. Inherently such designs suffer from excess structure and problems typically associated with compromised designs. Being built-in rather than portable, this type of rack, as with the previously described racks, also requires that dishes be removed and either reracked or restacked outside of the dish washer for storage or transportation. A more recent rack design is shown in U.S. Pat. No. 4,969,560. The dish rack here has three sawtooth shaped support members which hold plates about their periphery. Although this design works reasonably well in enabling dishes to be washed and transported, many problems still exist. For example, should the rack be abruptly rocked or tilted during transportation the dishes therein may ride over the upper supports thereby becoming dislodged from the rack. Also, when not in use these types of racks occupy a large amount of space, making their transportation and storage inefficient.
Accordingly, it is seen that a need still remains for a portable dish rack for use in dishwashers that can effectively and securely hold dishes of various sizes with minimal risk of breakage, which are readily placeable and removable from dishwashers, and which are efficiently stored when not in use. It is to the provision of such that the present invention is primarily directed.